Weather-related
accidents account for the majority of aviation fatalities
and most of these weather accidents involve General Aviation
aircraft. Since GA aircraft are not equipped with voice or
data recorders, the specific causes for these accidents are
often unknown. In order to develop preventative measures,
it is therefore extremely important to gather insights and
data from pilots who were involved in weather-related incidents.

In
conjunction with the FAA, NASA/ASRS will examine a variety
of GA weather encounter issues. Some of the factors to be
analyzed include: VFR in IMC, icing encounters, unexpected
ceiling and/or visibility issues, disorientation, loss of
positional or situational awareness, loss of aircraft control,
controlled flight toward terrain (CFTT), and severe turbulence.
In short, any weather encounter that affects safety of flight
will be analyzed. Contributing elements such as pilot experience,
training, proficiency, weather briefings, and aircraft equipment
will also be studied.

While
most aircraft involved in weather encounter events reported
to ASRS are expected to be light single and twin, piston-engine
aircraft, all aircraft and rotorcraft involved in FAR Part
91 and 135 operations are to be included in this study piston,
turboprop, or jet.

The
time frame for this effort is from April 2005 through September
2005.

In
order to provide the level of detail needed to fully understand
the hazardous situation and the factors affecting it, ASRS
will begin contacting pilots who report general aviation weather
encounters to request their voluntary participation in completing
a written survey questionnaire. Reporter participation in
the survey is strongly encouraged.

All
identifying information (names, company affiliations, etc.)
will be removed before the ASRS research data is given to
the FAA.

To
support FAA and industry efforts to improve awareness, knowledge,
training, and procedures related to aviation weather, ASRS
strongly encourages general aviation pilots who experience
adverse weather encounters to report these incidents to the
Program and to participate in the Weather Encounters Study.

Way
back in the days of the Wright Flyer and the Boeing 737-200,
aircraft control was directly dependent upon real-time pilot
input. The "pilot action - aircraft reaction" algorithm
tended to reduce the possibility of distraction or complacency
during aircraft maneuvering.

In
today's fully automated, glass cockpit environment, the pilot's
role has become more supervisory and the requirement for direct
control input is diminished or absent. When automation functions
reliably, as it does most of the time, it can induce pilots
to be less alert in monitoring its behavior. As these recent
ASRS reports illustrate, pilots must guard against distractions
and automation complacency in order to ensure that the aircraft
performs as directed and anticipated.

Lessons
from the Line

Altitude
and track or heading deviations continue to represent a significant
percentage of the incidents submitted to ASRS. In each of
the following reports, the deviations resulted when automation
failed to perform as expected. Each report also contains an
observation worth noting.

We
were cruising at FL350 when Center directed a descent to
FL250. The Captain set the new altitude in the FCU and I
pushed the Altitude button for a managed descent. We were
discussing the arrival, weather, etc., when Center asked
us what our assigned altitude was. I looked up and saw that
we were still at FL 350.... We began an immediate descent
and Center then gave us a vector.... I know I pushed the
Altitude button on the FCU. My mistake was that I didn't
confirm a reaction from the airplane....The
lesson is obvious, as it always is ­ never trust the
airplane to do (or not do) something and be extra diligent
to double check it, especially when tired, hurried, or late
which seems to be the company standard anymore....

ATC
cleared us to cross five miles south of FIX at 13,000 feet.
We were at 15,000 feet and the restriction was entered into
the FMS. We began discussing landing data and ended up crossing
the restriction at 15,000 feet. ATC asked our altitude and
we immediately descended to 13,000 feet with a rapid descent
rate. The controller gave us a heading off the route....
Our discussion distracted us from
monitoring the aircraft's response to our input.

We
were cruising at FL280 when ATC instructed us to cross 45
miles south of FIX at FL240. The Captain entered a crossing
of 240 at FIX -45 in the FMS. It was verified and executed.
I also verified that VNAV was still engaged. Approximately
five miles south of FIX, ATC called and asked what distance
we were from FIX. The aircraft had not started the descent.
I replied that we had just noticed the same thing and were
in a rapid descent to FL240. Monitoring
changes of aircraft attitude should take precedence over
all other activities.

ATC
instructed us to descend from FL350 to FL340. The pilot
flying set FL340 in the auto-pilot altitude window. The
pilot not flying verified it and saw the pilot flying enter
the new altitude in the FMS Cruise Altitude page and then
push the VNAV button. We both became distracted for a couple
of minutes and then ATC radioed a repeat of our clearance.
We realized that the aircraft had not begun to descend as
programmed....We re-learned a
lesson - it's easy to become complacent with the automation.

We
were given a descent clearance from FL380 to cross FIX at
FL350. The auto-pilot was engaged and programmed for the
descent. By the time we realized that the aircraft had not
started the descent, it was too late to make the crossing
restriction.... Lesson learned:
you still have to keep an eye on the airplane.

After
leveling off at our cruise altitude, we were assigned a
290- degree heading to intercept the INTXN transition....
The auto-pilot was engaged and heading mode was active on
the flight director. The heading bug was set to 290 degrees
and the NAV capture button was pressed and illuminated to
enable intercept of the course toward INTXN. A brief discussion
about the approach charts ensued and ended with ATC advising
us that we had passed through the INTXN transition.... For
some reason the flight director did not capture and intercept
the commanded course.... We both
should have been monitoring the intercept.... It is very
important to stay alert.

On
descent, Center gave us clearance to cross FIX at 8,000
feet. The First Officer (pilot flying) used LVL CHG (Level
Change) to select it and I visually confirmed this. I then
looked away to continue filing a report in the ACARS. I
believe the First Officer was putting away some of his charts.
Then he made a comment that alluded to the fact that the
airplane wasn't doing what he asked to do. It was only descending
at 500 feet per minute. By the time he caught this and corrected
for it, we were going to miss the altitude restriction.
I notified Center and they were not too pleased.... Make
sure the autoflight system is doing what you want it to
do